Composition containing dispersed pigment and preparation method thereof

ABSTRACT

A composition containing dispersed pigment comprises, as a dispersing agent, a reaction product of at least one polyamine having two or more primary amino groups and/or secondary amino groups and at least one polyisocyanate having two or more isocyanate groups.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention concerns a composition containing pigment dispersed in areaction product of polyamines and polyisocyanates. More particularly,this invention relates to a composition containing at least a pigmentdispersed in a dispersing agent, which possesses excellent dispersionstability of the pigment, lower thixotropy and an excellent flowproperty.

2. Description of the Prior Art

In conventional compositions containing dispersed pigments composed ofpigments, resins and solvents, if the dispersibility of the pigment tothe resin is poor, the composition containing the dispersed pigmentexhibits remarkable thixotropy due to the flocculation of the pigment.Further, since paint films formed by applying a composition containing adispersed pigment having flocculated pigments cause various problemssuch as degradation in the gloss, a decrease in the distinctiveness ofimage, reduction in the color strength, flooding, etc., sufficientperformance of the pigment can not be obtained with such compositionscontaining the dispersed pigment.

In order to overcome the foregoing problems, various inventions havebeen proposed as described below.

(1) There has been a method of incorporating certain pigment derivativesinto pigment as shown in Japanese Patent Laid-Open No. 18736/1976, butthis method can not be applied to general use for various pigments sincesuch pigment derivatives are colored by those structures.

(2) There has also been disclosed, for example, in Japanese PatentLaid-Open No. 160396/1975 and British Patent Specification Nos. 1393401and 1393402 a technique of utilizing, as a dispersing agent, thosecompounds obtained by reacting three groups of compounds, that is,organic compounds having at least two isocyanate groups, i.e.,polyisocyanate (group A), organic compounds having at least twofunctional groups reactive with the isocyanate groups, for example,amino groups or hydroxyl groups (group B) and polymers (group C) havingone functional group reactive with the isocyanate groups. Thesedispersing agents have, however, the defect as described below.

The design concept for the dispersing agent of this type is to prepare ablock structure comprising chains that can be solvated with solvents andpolar anchor group portions adsorptive to the pigment as stated by A.Topham in "Progress in Organic Coatings", Vol. 5, (1977), pp 237-243.When employing this technique, it is necessary to prepare a compositioncontaining dispersed pigment comprising the dispersing agent asdescribed above, the solvent and the pigment and, in the case ofpreparing paints using the composition, it is generally furthernecessary to add various types of resins as the film forming vehicles.In this case, the type and amount of vehicle resins to be added as thefilm forming ingredients are restricted in view of the compatibilitybetween the film forming resins and the polymer constituting thedispersing agent. Accordingly, it has been difficult to use suchdispersing agents for general purpose application. Particularly, theyhave insufficient effects on the pigments and poor dispersibility, forexample, with quinacridone pigments. Further, problems may occur in thedurability or other areas of film performance of the paint filmscontaining a large amount of dispersing agent used for dispersingpigments as described in the prior art and literature. A certaincomplexity of production steps required to utilize these priortechniques is imposed, such as the requirement for the prior synthesisof the dispersing agent, as well as the prior synthesis of theingredients, that is, the polymers of the group C, necessary forsynthesizing the dispersing agent.

Moreover, the conventional dispersing agents have previously beensynthesized and have been used by being blended with pigments andvehicle resins upon dispersing the pigments. Since the conventionaldispersing agents have been prepared and used in these ways, when theyare used, for example, for the preparation of paints, they produceundesirable effects on the paints and the condition of the paint filmsdue to the restriction caused from the composition of the dispersingagents, such as poor compatibility between the dispersing agents and thevehicle resins, the restrictions on the types of solvents to be used ora reduction in the water resistance of the paint films.

SUMMARY OF THE INVENTION

One object of this invention is to provide a composition containingdispersed pigment having an excellent dispersion stability for thepigments.

Another object of this invention is to provide a method of preparing acomposition containing dispersed pigment that is excellent in dispersionstability of the pigments.

The term "dispersion stability" used herein means that a pigment can befinely dispersed and that the dispersed pigment is present, in a stablestate with no flocculation.

This invention concerns a composition containing dispersed pigmentcontaining, as a dispersing agent, one or more reaction productsobtained from at least one organic compound having two or more primaryamino groups and/or secondary amino groups (hereinafter referred to aspolyamines) and at least one organic compound having two or moreisocyanate groups (hereinafter referred to as polyisocyanates).

In another aspect, this invention concerns a composition containingdispersed pigment, which comprises pigments, vehicle resins, reactionproducts as described above and, optionally, organic solvents.

In a further aspect, this invention concerns a method of preparing acomposition containing dispersed pigments, which comprises mixing anddispersing pigments, vehicle resins, at least one polyamine, at leastone polyisocyanate and, optionally, organic solvents.

DETAILED DESCRIPTION OF THE INVENTION Pigments

In this invention, various types of inorganic pigments or organicpigments that are usually employed in the paint or printing ink industrycan be used. The inorganic pigments can include, for example, zincwhite, titanium dioxide, antimony white, iron oxide red, iron oxideyellow, transparent iron oxide, red lead, cadmium yellow, zinc sulfide,lithopone, barium sulfate, lead sulfate, barium carbonate, white lead,alumina white and carbon black. The organic pigments can include, forexample, various pigments such as azo series, polycondensation azoseries, metal complex azo series, benzimidazolone series, phthalocyanineblue series, phthalocyanine green series, thioindigo series,anthraquinone series, flavanthrone series, indanthrene series,anthrapyrimidine series, pyranthrone series, isoindolinone series,perylene series, perinone series and quinacridone.

While this invention is mainly directed, among those described above, tothe use of carbon black and organic pigments which have been consideredas difficult to disperse, this invention can of course be applied alsoto other pigments with improved dispersibility of the pigments.

Resins

As the vehicle resins usable in this invention, those vehicle resinsusually employed in the preparation of paints and printing inks canadvantageously be used and include, for example, alkyd resins, polyesterresins, acrylic resins, vinyl resins such as polyvinyl chloride,polyvinyl acetate, chlorinated polyolefins and polyamide resins.

Polyamines

The organic compound having two or more primary and/or secondary aminogroups, that is, polyamines, usable in this invention can includevarious kinds of polyamines, for example, ethylenediamine,1,3-propylenediamine, hexamethylenediamine, diethylenetriamine,triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine,bisaminopropylpiperazine, bisaminopyridine, xylylenediamine,metaphenylenediamine, 4,4'-diaminodiphenylmethane and polyethyleneimine.Among them, those polyamines having three or more of primary and/orsecondary amino groups or those polyamines having two or more primaryand/or secondary amino groups and one or more tertiary amino groups areused preferably. Preferred polyamines include, for example,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,pentaethylenehexamine, polyethyleneimine prepared through cationicpolymerization of ethyleneimine, that is, commercially availablepolyethyleneimine represented by the structure as shown in the followingformula (A), bisaminopropyl piperazine and bisaminopyridine: ##STR1##

Polyisocyanates

The polyisocyanates usable in this invention can include, for example,those diisocyanate compounds such as tolylene diisocyanate (TDI),4,4-diphenyl methane diisocyanate (MDI), xylylene diisocyanate (XDI),hexamethylene diisocyanate, hydrogenated MDI, hydrogenated TDI,hydrogenated XDI and isophorone diisocyanate. More preferably, the useof higher polyfunctional polyisocyanate compounds is advantageous.

Such compounds can include, for example, those compounds prepared byreacting polyols with diisocyanates such as represented by formulas(1)-(4), those compounds prepared through biuret reaction fromdiisocyanates, for example, represented by formula (5), those compoundsprepared through the ring formation of diisocyanates such as compoundsrepresented by the formulas (6)-(8) and those compounds represented bythe formulas (9) and (10). ##STR2## where n represents an integer from 1to 4.

Commercially available products containing the abovementioned compoundsas the main ingredient are exemplified as described below:

Coronate HL (trade name of products available from Nippon PolyurethaneIndustries Co., Ltd.) containing the compound of formula (1) as the mainingredient;

Sumidur L (trade name of products available from Sumitomo Bayer UrethaneCo., Ltd.) containing the compound of formula (2) as the mainingredient;

Takenate D 110N (trade name of products available from Takeda ChemicalIndustries Co., Ltd.) containing the compound of formula (3) as the mainingredient;

Takenate D-120N (trade name of products available from Takeda ChemicalIndustries Co., Ltd.) containing the compound of formula (4) as the mainingredient;

Takenate D-165N, Takenate D-165N-90CX (trade name of products availablefrom Takeda Chemical Industries Co., Ltd.), and Sumidur N (trade name ofproducts available from Sumitomo Bayer Urethane Co., Ltd.) containingthe compound of formula (5) as the main ingredient;

Coronate EH (trade name of products available from Nippon PolyurethaneIndustries Co., Ltd.) containing the compound of formula (6) as the mainingredient;

Desmodule IL (trade name of products available from Bayer AG) containingthe compound of formula (7) as the main ingredient;

Desmodule HL (trade name of products available from Bayer AG) containingthe compound of formula (8) as the main ingredient;

Desmodule R (trade name of products available from Bayer AG) containingthe compound of the formula (9) as the main ingredient;

Millionate MR (trade name of products available from Nippon PolyurethaneIndustries Co., Ltd.) containing the compound of the formula (10) as themain ingredient.

Each of the commercial products is not a pure chemical but a mixture ofa compound of the structure shown by each of the formulas as the mainingredient and a compound of a structure similar to that of the mainingredient, and the respective products have an average number offunctional groups (number of isocyanate groups per average molecularweight) of from 2.5 to 6.

Organic Solvents

The solvents usable in this invention are those ordinarily employed inthe paint and printing ink industries, and can include, for example,hydrocarbon series solvents such as toluene, xylene, Solvesso 100 andSolvesso 150 (trade name of products available from Esso Standard Co.Ltd.), ester series solvents such as ethyl acetate and butyl acetate,ketone series solvents such as methyl ethyl ketone and methyl isobutylketone and ether series solvents such as ethylene glycol monoethyl etherand ethylene glycol mono-normal butyl ether. These solvents may be usedalone or as a mixture of two or more different solvents.

Mixing Ratio of Polyamines and Polyisocyanates

The polyamines and polyisocyanates are preferably used in such ablending ratio whereby primary and/or secondary amino groups are presentat least in an amount equivalent to the isocyanate groups, and it isgenerally preferred to use the amino groups in excess of an amountequivalent to the isocyanate groups.

In the case of using polyamines containing the primary and/or secondaryamino groups with an excess blending of the amino groups to theisocyanate groups, it is generally advantageous to use and blendpolyamines containing three or more primary and/or secondary aminogroups such that at least two of the amino groups can react with theisocyanate groups.

In the case of using polyamines containing primary and/or secondaryamino groups and tertiary amino groups, it is generally advantageous toblend polyisocyanates such that the isocyanate groups are present in anamount equal to or less than equivalent to the primary and/or secondaryamino groups. More preferably, a polyamine containing four or moreprimary and/or secondary amino groups and a polyisocyanate having anaverage number of functional groups (that is, the number of isocyanategroups/average molecular weight) of 2.5 or 2.5-6 are used and blendedsuch that at least three amino groups of the polyamine are reacted withthe isocyanate groups. Also in these cases, the total amount of theprimary amino groups, the secondary amino groups and the tertiary aminogroups before reaction is preferably from 1.05 to 5 times the equivalentamount of the isocyanate groups.

Mixing Ratio of Pigments and Other Ingredients

The mixing ratio between the total amount of the polyamines and thepolyisocyanates and the pigments, based on 100% by weight of the totalamount of the polyamines, the polyisocyanates and the pigments, has tobe such that from 99.9 to 70% by weight of the pigments are mixed withfrom 0.1 to 30% by weight of the total amount of the polyamines and thepolyisocyanates. A more preferred mixing ratio is from 99 to 80 parts byweight of the pigments based on from 1 to 20 parts by weight of thetotal amount of the polyamines and the polyisocyanates.

If the amount of the polyamines and the polyisocyanates used is lessthan 0.1% by weight, no sufficient effect of this invention can beattained. While on the other hand, if it exceeds 30% by weight, theviscosity of the composition containing the dispersed pigment issignificantly and undesirably increased.

Mixing Ratio of Resins and Pigments

The mixing ratio between the vehicle resins and the pigments in thecomposition containing the dispersed pigment according to this inventionusually ranges from 98 to 10 parts by weight of the pigments based onfrom 2 to 90 parts by weight of the solid component in the vehicleresins in the preparation or the like for reasons of economy. A morepreferred blending ratio ranges from 97 to 30 parts by weight of thepigments based on from 3 to 70 parts by weight of the solid component inthe vehicle resins.

Reaction of Polyamines and Polyisocyanates

Vehicle resins generally employed in the paint or printing inkindustries have hydroxyl groups or carboxyl groups as the functionalgroups, which are in most cases reactive with isocyanate groups.However, since the reactivity between the amines and the isocyanates issignificantly higher than the reactivity between the vehicle resins andthe isocyanates, if the reaction is carried out between the amines andthe isocyanates under the coexistence of the vehicle resins or pigments,substantial reactions occur only between the amines and the isocyanates.This can be confirmed by determining the amount of unreacted aminogroups after the reaction between the amines and the isocyanate bypotentiometric titration as shown in Examples 2 and 3. That is, theamount of the unreacted amino groups is substantially equal to thedifference between the amount of the amino groups and that of theisocyanate groups used for the reaction.

Although the amines and the isocyanates generally cause a rapid chemicalreaction at a room temperature, the temperature may be increased ororganotin compounds or the like may be used as a catalyst in a casewhere it is required to complete the chemical reaction between thereactants more quickly.

Materials prepared by mixing and reacting the amines and the isocyanatesin the absence of pigments and vehicles are generally difficult todissolve in the solvents usually employed in the paint and printing inkindustries. For instance, when the polyamines and polyisocyanates arereacted in the absence of vehicle resins a solvent such as toluene,precipitation results. A composition containing dispersed pigmentsuperior to conventional compositions can be obtained by adding vehicleresins, pigments and an optional organic solvent to the precipitate, andthen dispersing.

While on the other hand, when the polyamines and the polyisocyanates arereacted in solutions containing vehicle resins and, optionally, organicsolvents, the materials resulting from the reaction are dissolved orfinely dispersed in the solution of the resins. Particularly, in whenthe polyamines and the polyisocyanates are reacted at such a blendingratio as to leave the amino groups in the vehicle resins having polarfunctional groups such as carboxyl groups and, optionally, in organicsolvents, the reaction products are dissolved more and are excellent fordispersing the pigments.

It has been found that when the pigments are dispersed in a mixturecomprising the reaction products of the polyamines and polyisocyanates,the vehicles resins and, optionally, organic solvents as describedabove, the reaction products can provide the effect of stabilizing thedispersed pigments.

Preparation of Composition containing Dispersed Pigment

A particularly preferred method for preparing a composition containingdispersed pigment comprises adding polyamines and polyisocyanates to amixture of pigments, a solution of vehicle resins and an optionalorganic solvent while the mixture is being dispersed, or comprisesadding polyamines and polyisocyanates to a mixture of vehicle resins andan optional organic solvent, and then adding pigments to the mixture,and after that, dispersing the pigments.

As the dispersing equipment for pigments in this case, dispersingequipment usually employed in the paint or printing industries, forexample, sand grinding mill, ball mill, roll mill, attritor anddissolver can be used as required.

Advantage of the Invention

In accordance with this invention, a composition containing dispersedpigment excellent in dispersion stability and having a preferred flowingproperty can be obtained in an extremely simple process.

Further, the composition containing the dispersed pigment according tothis invention is applied to the paint, (1) by the method of formingreaction products of the polyamines and the polyisocyanates having highdispersibility in the vehicle resins used, or (2) by the method ofdispersing the pigments by mixing the vehicle resins into the reactionproducts of the polyamines and the isocyanates. This invention, whenpracticed in such embodiments, can provide various industrial advantagessuch as simplification of the production steps which have hithertobrought about problems in the prior art, as well as improvements in thedispersibility and the stability in dispersion of the pigments, andelimination of the restriction on resins used together caused by thecompatibility and the like.

Furthermore, since the blending ratio of the dispersing agent is from0.1 to 30% by weight based on the total amount of the pigments anddispersing agent in this invention, while about 4.8 to 50% by weight ofdispersing agent based on the total amount of the pigments anddispersing agent have been required in the prior art, the amount ofvehicle resins used and the range for selecting them can be greatlyextended.

Accordingly, the durability and other performance properties of thepaint films when formed with the composition containing dispersedpigments according to this invention do not substantially suffer fromundesired effects by the composition containing dispersed pigment.Paint, printing ink, and the like prepared by using the compositioncontaining the dispersed pigment according to this invention can providepaint films excellent in gloss, distinctiveness of image, colorstrength, flooding and the like.

Differing from the dispersing agents of the prior art, the dispersingagent according to this invention can be synthesized in the process ofdispersing the pigment through the direct mixing of specific startingmaterials with pigments, by which the composition containing dispersedpigment can be prepared in situ. Alternatively, the dispersing agent ofthis invention can previously be synthesized in a solvent, which canthen be used for the preparation of the composition containing dispersedpigment. Furthermore, the dispersing agent of this invention can easilybe synthesized in the presence of a wide variety of vehicle resins foruse in the paint or the like, through which drawbacks involved in theconventional dispersing agents can be eliminated.

EMBODIMENT OF THE INVENTION

The following examples of this invention and Comparative Examples shownbelow are given solely for the easy understanding of this invention, andare thus in no way restrictive.

In the following Examples and Comparative Examples, "part" means partsby weight and "%" means % by weight unless otherwise specified.

EXAMPLE 1

50 parts of a short oil alkyd resin modified with coconut oil (acidvalue 8, a hydroxy value 80, 60% solid content), 30 parts of methylisobutyl ketone and 20 parts of Cinquasia red Y (trade name of productsof quinacridone series organic pigment, manufactured by E. I. du Pont deNemours & Company) were subjected to dispersing treatment by a sandgrind mill for 10 min and, thereafter, 0.28 parts of ethylene diaminewere added to the thus formed mixture. Further, while continuing thedispersing treatment, 1.22 parts of 4,4'-methylenebis[cyclohexylisocyanate] (hydrogenated MDI) were added to the mixtureformed by the mixing treatment as described above, and the dispersingtreatment was continued for a further 20 minutes. A compositioncontaining the dispersed pigment (1) was thus prepared.

For comparison, the same 50 parts of the coconut oil modified alkydresin, 30 parts of the methyl isobutyl ketone and 20 parts of theCinquasia red Y were subjected to the dispersing treatment in a sandgrind mill for 30 minutes to prepare a composition containing thedispersed pigment (2). The viscosity of the composition containingdispersed pigment (1) and that of the composition containing dispersedpigment (2) were measured by a Model E viscometer (manufactured by TokyoKeiki Co., Ltd.). The results are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                        Roter Speed     5       rpm    50     rpm                                     Composition containing                                                                        160     cps    145    cps                                     dispersed pigment (1)                                                         Composition containing                                                                        696     cps    132    cps                                     dispersed pigment (2)                                                         ______________________________________                                    

It is apparent from the results of the above-described experiment thatthe composition containing dispersed pigment (1) prepared by the methodaccording to this invention has an extremely excellent flowing propertywith lower thixotropy.

EXAMPLE 2

0.63 parts of tetraethylenepentamine were added to a mixture of 50 partsof the coconut oil modified alkyd resin as used in Example 1 and 30parts of Solvesso 100 (trade name of products available from EssoStandard Co., Ltd.) and 0.87 parts of 4,4'-methylenebis[cyclohexylisocyanate] (hydrogenated MDI) were added to the thusobtained mixture being stirred with a dissolver. When measuring theamount of amino groups contained in the thus obtained resin solution inacetic acid by way of potentiometric titration using perchloric acid asa tritration reagent, 0.123 mmol of perchloric acid was required forneutralizing 1 g of the resin solution. The amount is equal to thedifference between the amount of the amino groups in thetetraethylene-pentamine and the amount of the isocyanate groups added.

Since it was confirmed that the alkyd resin and Solvesso 100 had noamino groups by way of the potentiometric titration, it was ensured thatthe isocyanate groups added had reacted partially with the amino groupsof tetraethylenepentamine. 20 parts of the same pigments as in Example 1were added to 81.5 parts of the resin solution as described above andthe thus obtained mixture was subjected to dispersing by a sand grindingmill for 30 minutes to thereby obtain a composition containing thedispersed pigment (3).

Further, a composition containing dispersed pigment (4) was obtainedwith the same procedures as above except for using 0.4 parts oftetraethylenepentamine and 1.1 parts of 4,4'-methylenebis[cyclohexylisocyanate] (hydrogenated MDI). Further, a compositioncontaining dispersed pigment (5) was obtained in the same procedureswhile replacing tetraethylenepentamine with 0.28 parts of ethylenediamine and using 1.22 parts of 4,4'-methylene bis[cyclohexylisocyanate](hydrogenated MDI).

While on the other hand, 20 parts of the same pigment as described abovewere added to 50 parts of the alkyd resin and 30 parts of the Solvesso100 also as described above and the thus obtained mixture was subjectedto the dispersing treatment in a sand grind mill for 30 minutes toobtain a composition containing dispersed pigment (6).

The viscosity for each of the compositions containing dispersed pigmentwas measured by a Model E viscometer manufactured by Tokyo Keiki Co.,Ltd. The results are shown in Table 2.

                  TABLE 2                                                         ______________________________________                                        Roter Speed     5       rpm    50     rpm                                     Composition containing                                                                        387     cps    315    cps                                     dispersed pigment (3)                                                         Composition containing                                                                        365     cps    309    cps                                     dispersed pigment (4)                                                         Composition containing                                                                        872     cps    415    cps                                     dispersed pigment (5)                                                         Composition containing                                                                        731     cps    230    cps                                     dispersed pigment (6)                                                         ______________________________________                                    

The compositions containing dispersed pigment (3) and (4) exhibitedexcellent flowing property with lower thixotropy.

50 parts of the same coconut oil modified alkyl resin as described aboveand 30 parts of Uvan 128, i.e., trade name of melamine formaldehyderesin varnish manufactured by Mitsui Toatsu Chemical Co., Ltd., werecombined to thereby prepare a baking type alkyd melamine resin paint.

Each of the paints are described above was diluted with a thinner to aviscosity suitable for spraying and then spray coated on a tin plate.The thus coated tin plate was kept in the air at 140° C. for 30 minutesand, thereafter, 20° gloss and 60° gloss for the paint film weremeasured.

Further, after applying each of the diluted paints on the tin plate byway of flow coating which means such a coating process of puttingapprox. 5 cc of paint on a tin plate sized 50 mm×150 mm, coating the tinplate by disposing the plate vertically thereby causing the paint toflow downwardly and then keeping it as it is for 10 minutes), the coatedtin plate was kept in air at 140° C. for 30 minutes and the paint filmwas baked. The 20° gloss of the paint film thus obtained was measured.The results are as shown in Table 3.

                  TABLE 3                                                         ______________________________________                                                      Spray coating                                                                           Flow coating                                                        20°                                                                           60°                                                                           20°                                        ______________________________________                                        Composition containing                                                                        85       92     79                                            dispersed pigment (3)                                                         Composition containing                                                                        87       93     82                                            dispersed pigment (4)                                                         Composition containing                                                                        77       89     45                                            dispersed pigment (5)                                                         Composition containing                                                                        72       89     22                                            dispersed pigment (6)                                                         ______________________________________                                    

It is apparent from Table 3 that the compositions containing dispersedpigment (3) and (4) are excellent, with the composition containingdispersed pigment (4) being particularly excellent.

While tetraethylenepentamine and polyisocyanate compounds were blendedsuch that two out of the five amino groups of tetraethylenepentaminewere reacted with the isocyanate groups in the composition containingdispersed pigment (3), tetraethylenepentamine and polyisocyanatecompounds were blended such that four amino groups of thetetraethylenepentamine were reacted in the composition containingdispersed pigment (4).

In this way, by reacting more amino groups contained in the polyamine,the effect of this invention can further be improved.

In the composition containing the dispersed pigment (5), ethylenediaminewas used and it was blended with the polyisocyante compound such thatall of the amino groups were reacted with the isocyanate groups.Although the composition containing dispersed pigment (5) was superioras compared with the composition containing dispersed pigment (6) ofthis invention, it was inferior to the compositions containing dispersedpigment (3) and (4).

These experiments demonstrated the fact that the use of amino groups inexcess with respect to the isocyanate groups is preferred so that thereaction product of the polyamine and the polyisocyanate contains aminogroups.

EXAMPLE 3

0.32 parts of tetraethylenepentamine were added to a mixture of 50 partsof the coconut oil modified alkyd resin as used in Example 1 and 30parts of Solvesso 100 (trade name of products manufactured by EssoStandard Co., Ltd.). 1.18 parts of a trimer ofhexamethylene-1,6-diisocyanate having a biuret structure, that is,Takenate D-165N-90CX (trade name of products available from TakedaChemical Industries Co., Ltd.) (amine equivalent 200) was added to thethus obtained mixture under stirring by a dissolver. The mixture wasstirred by the dissolver for further 30 minutes, produced a resinsolution (A).

The amount of the amino groups contained in one g of the thus obtainedresin solution (A) was measured by the method as described in Example 2.It was equivalent to 0.03 mmol of perchloric acid, which was equal tothe difference between the amount of the amino groups and that of theisocyanate groups added.

20 parts of the same pigment as in Example 1 were added to 81.5 parts ofthe resin solution (A) and the thus obtained mixture was subjected to adispersing treatment by the sand grind mill for 30 minutes to form acomposition containing dispersed pigment (7). The viscosity was measuredby a Model E viscometer manufactured by Tokyo Keiki Co., Ltd. Thecomposition containing dispersed pigment (7) had a viscosity lower thanthat for each of the compositions containing the dispersed pigment inExample 2 as shown in Table 4 and exhibited excellent flow property withlower thixotropy.

                  TABLE 4                                                         ______________________________________                                        Roter Speed     5       rpm    50     rpm                                     Composition containing                                                                        235     cps    218    cps                                     dispersed pigment (7)                                                         ______________________________________                                    

To 100 parts of the composition containing dispersed pigment (7) asdescribed above, were added the same 50 parts of the coconut oilmodified alkyd resin and 30 parts of the melamine formaldehyde resinvarnish as in Example 2 to prepare a baking type melamine alkyd resinpaint. The paint was diluted with a thinner to a viscosity suitable forspraying and spray coated onto a tin plate. The thus obtained tin platewas kept in air at 140° C. for 30 minutes, which baked the paint film.20° gloss and 60° gloss of the thus obtained paint film, as well as the20° gloss of the paint film obtained by the flow coating were measured.The results are shown in Table 5.

                  TABLE 5                                                         ______________________________________                                                    Spray coating Flow coating                                                    20° gloss                                                                      60° gloss                                                                        20° gloss                                ______________________________________                                        Composition containing                                                                      89        93        84                                          dispersed pigment (7)                                                         ______________________________________                                    

The composition containing dispersed pigment (7) exhibited superiorresults to the composition containing dispersed pigment (4) in Example 2by using a polyfunctional polyisocyanate having more than 2 isocyanategroups.

EXAMPLE 4

0.63 parts of tetraethylenepentamine were added to 30 parts of methylisobutyl ketone and the thus obtained mixture was stirred in adissolver. 0.87 parts of 4,4'-methylene bis[cyclohexylisocyanate](hydrogenated MDI) were applied to the above-mentioned mixture understirring. A rapid exothermic reaction occurred to form whiteprecipitates. To the thus obtained mixture of reaction product andmethyl ethyl ketone, were applied the same 50 parts of the coconutoil-modified alkyd resin and 20 parts of pigments are used in Example 1and 120 parts of glass beads of 1.5 mmφ. The thus obtained mixture wassubjected to a dispersing treatment in a paint shaker for 2 hours toform a composition containing dispersed pigment (8).

While on the other hand, the same 50 parts of the coconut oil-modifiedalkyd resin and 0.63 parts of tetraethylenepentamine as described abovewere added to 30 parts of methyl isobutyl ketone, and 0.87 parts of4,4'-methylene bis[cyclohexylisocyanate] (hydrogenated MDI) were addedto the thus formed mixture under stirring by a dissolver, followed bycontinued stirring for further 30 minutes. To the thus obtained resinsolution, were added 20 parts of the same pigment as in Example 1 and120 parts of glass beads of 1.5 mmφ and the obtained mixture was shakenin a paint shaker of 2 hours to prepare a composition containingdispersed pigment (9).

To each 100 parts of the composition containing dispersed pigment (2) inExample 1 and compositions containing dispersed pigments (8) and (9) inthis example, were added the same 50 parts of the coconut oil modifiedalkyl resin and 30 parts of melamine resin varnish as in Example 2, toprepare baking type melamine alkyd resin paints, respectively. Thepaints were diluted with a thinner to a viscosity suitable for spraying.Each of the thus obtained diluted paints was flow-coated on a tin plate(after putting about 5 cc of paint to the upper part of a tin platesized 50 mm×150 mm, the paint was caused to flow downwardly by disposingthe tin plate vertically to coat the tin plate and then kept as it wasfor 10 minutes). The thus coated tin plate was kept in air at 140° C.for 30 minutes and the paint film was baked. The 20° gloss of the thusobtained paint film is shown in the following Table 6.

                  TABLE 6                                                         ______________________________________                                                         20° gloss                                             ______________________________________                                        Composition containing                                                                           29                                                         dispersed pigment (2)                                                         Composition containing                                                                           69                                                         dispersed pigment (8)                                                         Composition containing                                                                           84                                                         dispersed pigment (9)                                                         ______________________________________                                    

As apparent from Table 6, the compositions containing dispersed pigment(8) and (9) had excellent performance, with the composition containingdispersed pigment (9) being particularly preferred.

EXAMPLE 5

To each 81.5 parts of the resin solution (A) in Example 3, was addedeach 20 parts of Novoperm orange HL-70 (trade name of azo series pigmentproducts, manufactured by Hoechst A.G.), Hostaperm yellow H-3G (tradename of azo series organic pigment of products manufactured by HoechstA.G.) and Paliogen red L-3910HD (trade name of perylene series organicpigment of products, manufactured by BASF AG), respectively. The thusobtained mixtures were subjected to the dispersing treatment in a ballmill for 24 hours to prepare compositions containing dispersed pigment(10), (12) and (14), respectively.

For the comparison, 20 parts of each of the pigments as described abovewere added to 50 parts of the coconut oil modified alkyd resin and 30parts of Solvesso 100 (trade name of products manufactured by EssoStandard Co., Ltd.). The thus obtained mixtures were subjected to thedispersing procedures in a ball mill for 24 hours to form compositionscontaining dispersed pigment (11), (13) and (15), respectively.

The viscosity for each of the compositions containing dispersed pigmentis shown in the following Table 7. Further, 50 parts of coconut oilmodified alkyd resin and 30 parts of melamine formaldehyde resin varnishwere added to the respective compositions containing dispersed pigmentas in Example 2, to prepare melamine alkyd resin paints. The thusprepared melamine alkyd resin paints were spray coated on tin plates andthe thus coated tin plates were kept in air at 140° C. for 30 minutes toeffect baking of the paint films. The 20° gloss and the 60° gloss of thepaint film thus obtained were measured. The results are also shown inthe following Table 7.

                  TABLE 7                                                         ______________________________________                                                 Composition           Spray                                                   containing            coating                                                 dispersed                                                                              Viscosity    20°                                                                           60°                              Pigment    pigment    5 rpm    50 rpm                                                                              gloss                                                                              gloss                               ______________________________________                                        Novoperm orange                                                                          (10)        127 cps 122 cps                                                                             88   93                                  HL-70      (11)        510 cps 166 cps                                                                             80   91                                  Hostaperm yellow                                                                         (12)        341 cps 290 cps                                                                             88   92                                  H-3G       (13)       1134 cps 324 cps                                                                             76   90                                  Paliogen red                                                                             (14)       1898 cps 615 cps                                                                             86   91                                  L-3910HD   (15)       2365 cps 586 cps                                                                             75   89                                  ______________________________________                                    

From the experiment as described above, it was found that thecomposition containing the dispersed pigment according to this inventionhad excellent performance as compared with compositions prepared usingconventional dispersing methods. of the pigments.

EXAMPLE 6

0.56 parts of diethylenetriamine were added to a mixture of 45 parts ofthe same alkyd resin in Example 1 and 45 parts of xylene and the thusobtained mixture was stirred by a dissolver. 3.65 parts formed from anadduct of 3 mol of hexamethylene diisocyanate and 1 mol of trimethylolpropane, that is, Coronate HL (trade name of products containing 25%ethyl acetate and 12.5% NCO, manufactured by Nippon PolyurethaneIndustries Co., Ltd.) were added to the above-mentioned mixture understirring by a dissolver, to obtain a resin solution. Then, 10 parts ofcarbon black MA-100 (trade name of products available from MitsubishiChemical Industries Ltd.) were added to the resin solution and the thusobtained mixture was subjected to a dispersing treatment in a sand grindmill for 30 minutes. In this manner, a composition containing dispersedpigment (16) was obtained. For the comparison, a composition containingdispersed pigment (17) was prepared in the same procedures as describedabove without adding polyamine and polyisocyanate.

The viscosity for each of the compositions was measured by a rotaryModel E viscometer (manufactured by Tokyo Keiki Co., Ltd.). The resultsare shown in the following Table 8.

                  TABLE 8                                                         ______________________________________                                        Roter Speed     5       rpm    50     rpm                                     Composition containing                                                                        75      cps    68     cps                                     dispersed pigment (16)                                                        Composition containing                                                                        895     cps    173    cps                                     dispersed pigment (17)                                                        ______________________________________                                    

EXAMPLE 7

50 parts of Acrydic A-405 (trade name of acrylic resin varnish products,available from Dainippon Ink & Chemicals, Inc.), 50 parts of xylene, 20parts of Hostaperm yellow H-3G (trade name of products available fromHoechst AG) were subjected to dispersing a treatment in a grind mill forfive minutes. 0.32 parts of tetraethylenepentamine were added to thethus obtained mixture and 1.72 parts of Sumidur (trade name of productscontaining 16.5% NCO, 12.5% of methyl glycol acetate and 12.5% ofxylene, manufactured by Sumitomo Bayer Urethane Co. Ltd.) were added tothe thus obtained mixture under the dispersing treatment and furthersubjected to a dispersing treatment for 25 minutes to obtain a dispersedpaste (18).

For the comparison, a composition containing dispersed pigment (19) wasprepared without adding amine and isocyanate. 90 parts of Acrydic A-105and 60 parts of Super Beckamine J-820 (trade name of products ofmelamine resin varnish, manufactured by Dainippon Ink & ChemicalIndustries Co., Ltd.) were added to the compositions containingdispersed pigments respectively, to prepare baking type melamine acrylicresin paints. Each of the paints was coated on a glass plate by using a6 mil applicator and baked at 150° C. for 30 minutes. The 20° gloss andthe 60° gloss for the obtained paint film were measured. The results areshown in Table 9.

                  TABLE 9                                                         ______________________________________                                                         20° gloss                                                                     60° gloss                                      ______________________________________                                        Composition containing                                                                           88       94                                                dispersed pigment (18)                                                        Composition containing                                                                           72       90                                                dispersed pigment (19)                                                        ______________________________________                                    

Table 9 shows that the composition containing dispersed pigment (18)according to this invention is superior to the Comparative Example, thatis, the composition containing dispersed pigment (19).

EXAMPLE 8

25 parts of toluene and a further 20 parts of Transparent oxide red30-1005 (trade name of products for transparent iron oxide pigment,manufactured by The Hilton-Davis Chemical Co.) were added to 60 parts ofAcrydic A-405 (trade name of products manufactured by Dainippon Ink &Chemicals Industries Co., Ltd.), and the thus obtained mixture wassubjected to a dispersing treatment by the sand grind mill for fiveminutes. 0.29 parts of tetraethylenepentamine were added to the thusobtained mixture and, while continuing the dispersing treatment to themixture, 1.21 parts of Coronate EH (trade name of products containing21.3% NCO manufactured by Nippon Polyurethane Industries Co., Ltd.) wereadded and subjected to dispersing a treatment for 25 minutes. In thisway, a composition containing dispersed pigment (20) as obtained.

For the comparison, a composition containing dispersed pigment (21) wasprepared by the same dispersing treatment by a sand grind mill withoutadding amine and isocyanate.

The viscosity for each of the compositions containing dispersed pigmentwas measured by a rotary Model E viscometer (manufactured by Tokyo KeikiCo., Ltd.), and 80 parts of Acrydic A-405 (trade name of productsmanufactured by Dainippon Ink & Chemical Industries Co., Ltd.) and 60parts of Super Beckamine J-820 (trade name of products manufactured byDainippon Ink & Chemical Industries Co., Ltd.) were added respectivelyto both of the compositions containing the dispersed pigment, to preparebaking type melamine acrylic resin paints. Each of the thus obtainedpaints was coated on a glass plate using a 6 mil applicator and baked at150° C. for 30 minutes. The 20° gloss and the 60° gloss for the paintfilm thus obtained were measured. The results are shown in Table 10.

                  TABLE 10                                                        ______________________________________                                                     Viscosity    Gloss                                                            5 rpm  50 rpm    20°                                                                           60°                               ______________________________________                                        Composition containing                                                                       1821 cps 1301 cps  126  119                                    dispersed pigment (20)                                                        Composition containing                                                                       2900 cps 1208 cps  117  108                                    dispersed pigment (21)                                                        ______________________________________                                    

Table 10 shows that the composition containing dispersed pigment (20)according to this invention is superior to the Comparative Example, thatis, the composition containing dispersed pigment (21).

COMPARATIVE EXAMPLE 1

The composition containing dispersed pigment according to thisinvention, the composition containing dispersed pigment prepared byusing the dispersing agent described in the example of Japanese PatentLaid-Open No. 160396/1975 and a composition containing dispersed pigmentprepared by using a dispersing agent described as Agent 1 in the BritishPatent Specification No. 1393401 were compared with each other. Each ofthe dispersing agents is referred to hereinafter with the numbers asdescribed below.

    ______________________________________                                        Dispersing Japanese Patent Laid-Open                                                                       Example 1                                        agent 1    No. 160396/1975                                                    Dispersing Japanese Patent Laid-Open                                                                       Example 8                                        agent 2    No. 160396/1975                                                    Dispersing British Patent No. 139401                                                                       Agent 1                                          agent 3                                                                       ______________________________________                                    

To 20 parts of Cinquasia red Y (trade name of products available from E.I. du Pont de Nemours & Co.) were added 10 parts of each of thedispersing agents as the solid content and then Solvesso 100 (trade nameof products available from Esso Standard Co., Ltd.), so as to make upthe entire amount to 60 parts. The thus obtained mixture was subjectedto dispersing treatment by a sand grind mill for 30 minutes and,thereafter, 40 parts of the coconut oil modified alkyd resin asdescribed in Example 1 was added and subjected to a dispersing treatmentfor 10 minutes to obtain compositions containing dispersed pigment (22),(23) and (24) in order of the number of dispersing agent. To each 100parts of the compositions containing dispersed pigment (3) and (4) inExample 2 and compositions containing dispersed pigment (22), (23) and(24) as described above, were added the same 50 parts of the coconut oilmodified alkyd resin and 30 parts of the melamine resin varnish as inExample 2, to prepare baking type alkyd melamine resin paints. Each ofthe paints was diluted with a thinner to a viscosity suitable forspraying, coated onto a tin plate by way of flow coating andspray-coated and baked at 140° C. for 30 minutes. Then, the 20° gloss onthe thus obtained paint film was measured. The results are shown inTable 11.

                  TABLE 11                                                        ______________________________________                                                       Flow coating                                                                           Spray coating                                                        20° gloss                                                                       20° gloss                                      ______________________________________                                        Composition containing                                                                         79         85                                                dispersed pigment (3)                                                         Composition containing                                                                         82         87                                                dispersed pigment (4)                                                         Composition containing                                                                         41         75                                                dispersed pigment (22)                                                        Composition containing                                                                         33         73                                                dispersed pigment (23)                                                        Composition containing                                                                         47         80                                                dispersed pigment (24)                                                        ______________________________________                                    

Table 11 shows that the dispersion composition according to thisinvention, that is, the compositions containing dispersed pigments (3)and (4) are more excellent.

What is claimed is:
 1. A resin composition containing a dispersedpigment, comprising:(a) from 0.1 to 30 parts by weight of a dispersingagent comprising the reaction product obtained by the reaction ofreactants consisting essentially of at least one polyamine having two ormore primary amino groups and/or secondary amino groups and at least onepolyisocyanate having two or more isocyanate groups, wherein said aminogroups are in excess with respect to said isocyanate groups so that saidreaction product contains amino groups; (b) from 70 to 99.9 parts byweight of a pigment; (c) a vehicle resin, the weight ratio of saidpigment to the vehicle resin solids being from 98:2 and 10:90; and (d)an organic solvent selected from the group consisting of hydrocarbons,esters, ketones and ethers.
 2. A resin composition containing adispersed pigment as defined in claim 1, wherein the polyamines areselected from the group consisting of aliphatic polyamines, heterocyclicpolyamines, aromatic polyamines and imines.
 3. A resin compositioncontaining a dispersed pigment as defined in claim 2, wherein thepolyamines are selected from the group consisting of ethylene diamine,1,3-propylene diamine, hexamethylene diamine, diethylene triamine,triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine,bisaminopropyl piperidine, bisamino pyridine, xylylene diamine,metaphenylene diamine, 4,4'-diaminodiphenyl methane andpolyethyleneimine.
 4. A resin composition containing a dispersed pigmentas defined in claim 2, wherein the polyamines are selected from thegroup consisting of diethylene triamine, triethylene tetramine,tetraethylene pentamine, pentaethylene hexamine, polyethyleneimine,bisaminopropyl piperidine and bisaminopyridine.
 5. A resin compositioncontaining a dispersed pigment as defined in claim 1, wherein thepolyisocyanate groups are selected from the groups consisting ofaromatic polyisocyanates, aliphatic polyisocyanates and cycloaliphaticpolyisocyanates.
 6. A resin composition containing a dispersed pigmentas defined in claim 1, wherein the polyisocyanates are selected from thegroup consisting of toluylene diisocyanate, 4,4'-diphenylmethanediisocyanate, xylylene diisocyanate, hexamethylene diisocyanate,4,4'-methylene bis cyclohexylisocyanate, hydrogenated TDI, hydrogenatedXDI and isophorone diisocyanate.
 7. A resin composition containingdispersed pigment as defined in claim 1, wherein the average number offunctional groups of the polyisocyanates is from 2.5 to
 6. 8. A resincomposition containing a dispersed pigment as defined in claim 1,wherein the polyamines are blended in such an amount so as to containamino groups from 1.05 to 5 times of a stoichiometrically equivalentamount relative to the isocyanate groups contained in thepolyisocyanates.
 9. A resin composition containing a dispersed pigmentas defined in claim 1, wherein the vehicle resin is selected from thegroup consisting of alkyd resins, polyester resins, acrylic resins,polyamide resins, polyvinyl acetate and chlorinated polyolefins.
 10. Amethod of preparing a resin composition containing a dispersed pigment,comprising mixing and dispersing (a) a reaction product obtained by thereaction of reactants consisting essentially of at least one polyaminehaving two or more primary amino groups and/or secondary amino groups,and at least one polyisocyanate having two or more isocyanate groups,said amino groups being in excess with respect to said isocyanate groupso that the reaction product between the polyamine and polyisocyanatecontains amino groups, (b) a pigment, (c) a vehicle resin, and (d) anorganic solvent, said polyamine and polyisocyanate being used in amountsso that the reaction product formed therebetween is present in an amountof 0.1 to 30 parts by weight based on 70 to 99.9 parts by weight of saidpigment, the weight ratio of said pigment to the vehicle resin solidsbeing from 98:2 to 10:90.
 11. A method for preparing a resin compositioncontaining a dispersed pigment as defined in claim 10, wherein theaverage number of functional groups of the polyisocyanates is from 2.5to
 6. 12. A method of preparing a resin composition containing adispersed pigment as defined in claim 10, wherein the polyamines areblended in such an amount so as to contain amino groups from 1.05 to 5times of the stoichiometrically equivalent amount relative to theisocyanate groups contained in the polyisocyanates.
 13. A method ofpreparing a resin composition containing a dispersed pigment as definedin claim 10, wherein the polyamines and the polyisocyanates are added toand dispersed in the pigment, the vehicle resin and the organic solventwhile mixing and dispersing them.
 14. A method of preparing a resincomposition containing a dispersed pigment as defined in claim 10,wherein the polyamines and the polyisocyanates are added to the resinand the organic solvent and, thereafter, the pigments are added anddispersed.
 15. A method of preparing a resin composition containing adispersed pigment as defined in claim 10, wherein the polyamines areselected from the group consisting of ethylene diamine,1,3-propylenediamine, hexamethylenediamine, diethylenetriamine,triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine,bisaminopropyl piperidine, bisaminopyridine, xylylenediamine,metaphenylenediamine, 4,4'-diaminodiphenyl methane andpolyethyleneimine.
 16. A method of preparing a resin compositioncontaining a dispersed pigment as defined in claim 10, wherein thepolyamines are selected from the group consisting of diethylenetriamine,triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine,polyethyleneimine, bisaminopropyl piperidine and bisaminopyridine.